A known problem with current publicly-accessible card-operated transaction terminals such as ATM terminals, is that it is possible for a third party to interpose an illicit card reader in the slot intended for inserting a card into the genuine card reader of the terminal. As a result, it is possible for the third party to capture information off the card and misuse it. An attack of this type is often referred to as a “shim” attack.
Of course, most card-based transaction terminals also require the input of a PIN (personal identification number) supposedly only known to the genuine card user. however, it is possible for a third party to gain knowledge of a PIN by covert observation during PIN entry by the user at a transaction terminal, this observation being effected either by the third party in person or by use of a concealed camera.
It is an object of the present invention to enable increased security for transactions effected at a publicly-accessible transaction terminal.